Mechanical devices for transmitting rotary motion from a driving shaft to a driven shaft are generally constituted on the basis of a gear train, a chain mechanism, or a screw and wheel system such as a worm gear. These devices include a large number of parts, particularly if certain additional characteristics are looked for, e.g. irreversibility (motion cannot be transmitted from the driven shaft to the driving shaft) or end-of-stroke indication (for motion over a limited stroke). Such characteristics are looked for, for example, in devices for controlling an electrical section switch.
An object of the present invention is thus to provide a member for transmitting rotary motion, which member is very simple mechanically, including a small number of parts, enabling irreversibility to be obtained without additional parts, and easily receiving an end-of-stroke indication.